Troubleshooting the Installation 5-11
Troubleshooting the Power Subsystem
—If the answer is no, but the fan trays are operating and the alphanumeric displays on
the RP and line cards are functional, the likely suspect is a faulty power supply
LED.
The MBus modules driving the alphanumeric di splays are powered by +5.2 VDC
from the power supply.
The fan trays are powered by +24 VDC from the DC-DC converter on the CSC;
hence, if the RP and the fan trays are operating normally, all internal DC voltages
are within tolerance.
You can issue the show environment command at the user EXEC mode prompt to
display temperature and voltage information for each installed card in the system.
—If the answer is no and there is no other obvi ous system activity, verify that the
rotary power switch on the power supply is in the fully clockwise ON (|) position.
If it is not, turn the power switch clockwise until you hear an audible click, ensuring
that the switch is in the full ON position and that the latching mechanism has been
engaged.
•If the rotary power switch is set correctly and the AC INPUT OK LED (on the AC-input
power supply) or the INPUT OK LED (on the DC-input power supply) still remains off,
examine the source AC or source DC power cable.
If the internal circuit breaker of the power supply has been tripped, you can reset it by
turning the rotary power supply switch OFF then ON again. However, note that the
tripping of the internal circuit breaker is a likely indication of an electrical problem in
the chassis.
•Turn the rotary power switch OFF (O); check the state of the source AC or DC circuit
breaker, as appropriate. Verify that the breaker is ON and that it has not been tripped.
Verify that the source circuit breaker has the proper current rating.
Note Each power supply in the Cisco12008 should be attached to a separate power
source.
•In systems powered by source AC, there might be an uninterruptable power supply
(UPS) for each installed AC-input power supply. Check that the UPS is functioning
correctly.